Help with DMX741U

[jibaro29]

Hi guys,

I'm in the process of installing this lnbf to my 1m dish. I'm getting a 1.2m from WS International next month but for now I just want to play with it. I guess I'm trying to get ready for "THE PROJECT" .

I down loaded the instructions (Installing DMX LNBF) from WS International website. That step was pretty simple. Now, what changes, if any, do I have to make to my Mercury ll receiver? Thanks.

 

[WSInternational]

To setup the LNBF parameters in your receiver, you will need to make sure you are using Universal LNBF setting in the receiver with the LO frequencies of 9750/10600MHz for the Ku band portion and setup the C band LO frequency to 5150MHz.

The DMX741U uses DiSEqC switching. The C band portion of the LNBF is on port "A" or "1" and the Ku band portion is on port "B" or "2".

Then based on the satellite you are wanting to point to, make sure you have the proper transponder frequency, symbol rate, and polarity and you'll be in business and ready to hunt for your signal.


:up

 

[Anole]

sometimes overlooked:

Robby gave the good technical answer, above.
Without all that info, you'd get no where.

But a very simple thing that is often overlooked, and gave me trouble the first time, is . . .
You really need two satellite entries, one configured for Ku band, and one configured for C-band.
That's for each satellite which has both C and Ku.
Obviously, you would only need one entry in the receiver, if you only wanted C OR Ku on a particular satellite.

The reason of course, is that each satellite acts as if it were two.
Each band has different settings for the diseqc switch, LO, and transponder frequencies.
I'm not aware of any receiver which lets you mix bands for a given satellite.

 

[jibaro29]

Thanks guys,

I am so what surprised that I can get C band on a 1M dish. So far I have been able to pick up a few transponders on SatMex5,6,AMC 4 and G-16. They are not strong signals but never the less they are there. What I'm surprise is that my Ku signal sucks. I thought it would be all the way around. So I am puzzled by it. Any ideas as to why and how I can fix this problem?

 

[Anole]

some suspicions:

From reading all the threads on the subject, over the years, I have some ideas.

- placement of the LNBF to get C-band is less critical than Ku
- getting the C/Ku LNBF at the exact focal point is quite difficult
- many users seem to put up with "sloppy", when "precise" is called for
- folks are lulled into a false sense of success once C-band signals are received
- the design and construction of existing dual band LNBFs is a real compromise

I always was confused that many who've been running C-band on 1.2m dishes often had a separate Ku LNB beside the C-band.
At first, I thought it was just that the BSC-621 LNBF's were the problem.

Most who put them on BUDs had Ku problems, as well.
Since C-band worked, some abandoned Ku.
Others got Ku to work, and were quiet as to how... maybe they were old time installers who were more skilled...

Linuxman documented the GeoSat CK-1 running both bands on the 8½' Birdview.
(more recently, the DMX741 as well)
- superior dish?
- superior LNBF?
- superior installer?
Yes. Maybe. Unquestionably.

Many mounting brackets put the LNBF near, but not at the focal point.
The LNBF needs to be aimed at the proper spot on the dish.
I suspect the fact the Ku LNB is deep inside the LNBF, makes aiming it at the dish, somewhat like threading a needle.

Suggestions:
Try measuring the LNB location horizontally. See that it's centered.
See if the elevation markings on your dish are still accurate (suggests the LNBF is high or low)
Carefully peak the LNBF signal on Ku, by adjusting it toward and away from the dish.